Students are asked to work on exterior and interior of the cube simultaneously. The cube carving exercise referred elsewhere in this chapter can also be utilised in this assignment. The external projections, recesses and cut-outs are now perceived from the inside of the cube. Then students are further asked to use two-dimensional planes, lines, threads and wires in the inner space of the cube. Ultimately students realise that one has to be careful in creating the external face which will be also seen from inside the room.

Experience of handling exterior and interior spaces simultaneously, should make students realise that there are certain forms like sphere, Pyramid and Cone that look totally different and are also difficult to handle internally. Whereas there are certain forms like steps, or cylinders which can create interesting internal space geometry.